JPH0665585A - Apparatus for dechlorination and waste gas conversion for waste plastic - Google Patents

Abstract

PURPOSE:To obtain a gaseous fuel by dechlorinating polyvinyl chloride in a waste plastic mixture and subjecting the resulting carbonization product to water gas conversion. CONSTITUTION:This apparatus has a dechlorination zone (a dechlorination screw feeder) 3 where a waste plastic mixture contg. polyvinyl chloride supplied together with a spherical water gas conversion catalyst is melted and dechlorinated and the resulting carbonization product is deposited on the catalyst; and a water gas conversion zone (a water gas conversion screw feeder) 5 where the carbonization product on the catalyst is reacted with water vapor 9 to generate water gas. An example of the catalyst is a porous spherical catalyst comprising nickel oxide, molybdenum oxide, iron oxide, chromium oxide, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for treating waste plastics discarded as municipal wastes or industrial wastes. More specifically, the present invention relates to an apparatus for treating waste plastics after dechlorination in a melting process of mixed waste plastics. The present invention relates to a dechlorination / water gasification device for waste plastics, which produces a gas fuel by carrying out a water gasification reaction of a carbide in the presence of a catalyst by thermal decomposition.

[0002]

2. Description of the Related Art Recently, as a method for treating mixed waste plastics, the use of waste plastics as fuel (solid fuel (RDF), oilification, gasification) has been reconsidered from the viewpoint of effective use of resources. However, the chlorine content of polyvinyl chloride contained in the mixed waste plastics causes hydrogen chloride during the oilification process and the use of solid fuel, which causes equipment corrosion and other problems, and the chlorine content of the obtained solid fuel increases. Therefore, waste plastics that do not contain polyvinyl chloride are currently being used as fuel.

Typical thermal decomposition methods for waste plastics include a fluidized bed type, a screw type, and a catalytic type using a catalyst.

On the other hand, the production of hydrogen is carried out by water gasification reaction of coke in the old days, and recently by partial oxidation reaction of natural gas / naphtha or heavy oil.

[0005]

When polyvinyl chloride is contained in the waste plastic, violent caulking occurs due to dechlorination of the polyvinyl chloride during melting of the waste plastic. How to continuously take out the carbide, which is the caulking component, and efficiently convert it into water gas is an important issue for practical use of waste plastics as a gas fuel.

The present invention has been made in view of the above circumstances, and an object of the present invention is to dechlorinate polyvinyl chloride contained in a mixed waste plastic, and then to remove the caulking component (carbide) produced as a water gas. An object of the present invention is to provide a device that can be converted into gas fuel by a chemical reaction.

[0007]

The present invention has been devised in order to solve the above-mentioned problems. When a waste plastic is melted, a porous water gasification catalyst having a spherical shape and a relatively large pore size is mixed with the waste plastic. The dechlorination and water gasification equipment for waste plastics, in which the molten plastic that has entered the pores of the catalyst is conquered, and the carbonized material is efficiently gasified into water while slanting the catalyst to which the resulting carbide is attached. .

That is, the waste plastic dechlorination / water gasification apparatus according to the present invention melts and dechlorines the polyvinyl chloride-containing waste plastic supplied together with the spherical water gasification catalyst and deposits the resulting carbide on the catalyst. It is provided with a dechlorination zone for deposition and a water gasification zone for reacting the carbide on the catalyst with water vapor to produce water gas.

A dechlorination screw feeder is preferably used as the dechlorination zone, and an inclined water gasification screw feeder is preferably used as the water gasification zone.

As the water gasification catalyst, nickel oxide,
Porous spherical particles made of molybdenum oxide, iron oxide, chromium oxide, etc. are used.

[0011]

EXAMPLE FIG. 1 shows an example of a dechlorination / water gasification apparatus for waste plastic according to the present invention. A waste plastic tank (2) equipped with a stirrer (16) is arranged above the heating furnace (1) equipped with a burner (1a), and a dechlorination screw feeder (3) is installed.
Is horizontally installed on the top of the heating furnace (1), and the water gasification screw feeder (5) is installed on the bottom of the heating furnace (1) in an inclined shape. Then, the bottom of the waste plastic tank (2) is connected to the beginning of the dechlorination screw feeder (3) via the drop path (4), and the end of the screw feeder (3) is connected by the vertical screw feeder (6). It is connected to the beginning of the water gasification screw feeder (5). A catalyst feed pipe (8) for returning the spherical catalyst (C) from the end of the water gasification screw feeder (5) to the waste plastic tank (2) is arranged. In the center of the heating furnace (1), a meandering pipe (7a) of the boiler (7) is arranged, and a steam supply pipe (9) is installed from the boiler (7) near the end of the water gasification screw feeder (5). It is distributed. Exhaust gas pipe from the middle part of the dechlorination screw feeder (3) and the top of the heating furnace (1) to the gas cleaning tower (10)
(11) (12) are respectively arranged, and the water gas recovery pipe (13) is arranged from the vicinity of the starting end of the water gasification screw feeder (5) to the water gas recovery device (15), and the recovery device (15) To the burner (1a) of the heating furnace (1) is provided a water gas supply pipe (14).

In the dechlorination / water gasification apparatus having the above-mentioned structure, the waste plastic containing polyvinyl chloride and the spherical catalyst (C) for water gasification are put into the waste plastic tank (2), where the stirrer (16 ) Is mixed. The mixture of waste plastic and spherical catalyst is followed by the waste plastic tank
Dechlorination screw feeder from (2) via drop path (4)
It falls to the beginning of (3). The waste plastic is heated to about 350 to 400 ° C. by the heat of the heating furnace (1) while being sent to the end portion by the feeder (3), melted and dechlorinated. Hydrogen chloride gas generated by dechlorination of waste plastic is sent to the gas cleaning tower (10) via the exhaust gas pipe (11), where it is cleaned and recovered as hydrochloric acid. A minute amount of hydrocarbons is also recovered by the recovery device.

The dechlorinated molten plastic is coked, and the resulting carbide is deposited on the surface of a porous water gasification spherical catalyst (C) having a relatively large pore size. Spherical catalyst with carbide attached is a dechlorination screw feeder
It is fed from the terminal end of (3) through a vertical screw feeder (6) to the starting end of an inclined water gasification screw feeder (5). Then, the spherical catalyst is heated to about 700 ° C. by the combustion heat of the heating furnace (1) while moving the feeder (5) to the end portion. Further, the steam generated by the heat of the heating furnace (1) is supplied from the boiler (7) through the steam supply pipe (9) to the vicinity of the end of the water gasification screw feeder (5). As a result, the carbide on the spherical catalyst reacts with water vapor to generate water gas. The water gas thus generated is
It is sent to the water gas recovery device (15) through the water gas recovery pipe (13), a part of it is supplied to the burner (1a) of the heating furnace (1) as fuel, and the rest is used for other purposes. The spherical catalyst (C) discharged from the end of the water gasification screw feeder (5) is returned to the waste plastic tank (2) again.

[0014]

EFFECT OF THE INVENTION Dechlorination of waste plastic according to the present invention
Since the water gasifier is configured as described above, dechlorination of polyvinyl chloride in mixed waste plastics is carried out by melt pyrolysis, and the generated coking component (carbide) is converted to gas fuel by water gasification reaction. You can In this way, it is possible to put the waste plastic into a gas fuel for practical use.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a dechlorination / water gasification device for waste plastic.

[Explanation of symbols]

 (1)… Heating furnace (2)… Waste plastic tank (3)… Dechlorination screw feeder (4)… Drop path (5)… Water gasification screw feeder (6)… Vertical screw feeder (7)… Boiler (8 )… Catalyst transfer pipe (9)… Steam supply pipe (10)… Gas cleaning tower (11) (12)… Exhaust gas pipe (13)… Water gas recovery pipe (14)… Water gas supply pipe (15)… Water gas Recovery device

Front page continuation (72) Inventor Toshio Hama 5-3-28 Nishikujo, Konohana-ku, Osaka City Hitachi Shipbuilding Co., Ltd. In the company

Claims (1)

[Claims] 1. A dechlorination zone for melting and dechlorinating polyvinyl chloride-containing waste plastic supplied together with a spherical water gasification catalyst, and adhering the resulting carbide onto the catalyst, and reacting the carbide on the catalyst with steam. A dechlorination / water gasification device for waste plastic, which is provided with a water gasification zone for generating water gas.